Sewing machine



FIG. 1 is a perspective front view of a sewing machine;

FIG. 2 is a perspective rear view;

FIG. 3 is a right side view;

FIG. 4 is a front view;

FIG. 5 is a rear view;

FIG. 6 is a left side view; and,

FIG. 7 is a top view. 

The ornamental design for a sewing machine, as shown and described. 